Overrunning clutch



Oct. 14, 1947. J. GRUENBERG OVER-RUNNING CLUTCH Filed Dec. 10, 1945INVENTOR. won J. GRUENBERG ATTORNEYS Patented Oct. 14, 1941 UNlTEDSTATES PATENT OFFICE OVERRUNNING CLUTCH Ivor J. Gruenberg, PleasantRidge, Mich., assignor to The (tear Grinding Machine Company, Hamtramck,Micln, a corporation of Michigan Application Decemberltl, 1945, SerialNo.-634,006 4 Claims. (c1; sm-45,1)

The invention relates to over-running clutches of that type in which thedrive and driven members have concentric cylindrical surfaces and spragsin the space therebetween for transmitting torque from one to the otherin one direction of rotation.

It is the object of the invention to obtain' a construction in which thesprags are normally held in released position so as tapermit freerelative rotation of the members without wear.

. It is a further object to obtain a construction in which aninstantaneous engagement of the clutch may be effected by a trippingaction and when once engaged will be maintained in engagement whileunder load but will be automatically disengaged on release of load. Withthese and other objects inxvicw the invention consists in theconstruction as hereinafter set forth.

In the drawings:

Fig. l is a longitudinal section partly in elevation of the clutch;

Fig. 2 is a side elevation thereof;

Fig. 3 is a perspective view of the helical 'memher which holds theclutch normally disengaged;

Fig. 4 is a view similar to Fig. 2 illustrating a modified construction.

A is a shaft. B is a member sleeved upon the shaft A and keyed orotherwise secured thereto to rotate therewith. C is an annular membersurrounding the member B but spacedtherefrom. D are sprags within thespace between the members Band C and E is a resilient member also withinthe space surrounding the sprags D and normally providing clearance fromthe inner face of the member 0. This member E is preferably a helicalcoil having the convolutions thereof of oblong cross section. Theopposite ends E and E of this cell extend axially outward therefrom andthe end E' engages a notch F in a radial flange F on the member B. Theresilient tension of the coil is sufficient to hold the sprags infrictional engagement with the member B while the coil itself is out offrictional engagement with the member C. If, however, an obstacle isplaced in the path of the end E of'the coil so as to temporarily arrestits rotation, this will expand the coil until it comes into lockingfrictional engagement with the inner surface of the member C. Thus,normally the shaft .A, sleeve B, sprag D and coil E will'revolvetogether free from trio-'- path of the portion E but adapted to be movedinto such path by a trip rod G. This will cause a substantiallyinstantaneous expansion of the coil into frictional engagement with themember 0, while the sprags D will form a driving engagement between themember B and said coil, Consequently, all of these parts will revolvetogether and will continue to so revolve after disengagement of the tripas long as the member C is under load. When, however, the load isreleased,

the coil E will contract thereby releasing its frictional engagementwith the member 0. It will be understood that the member C can beconnected in any suitable way with the load actuated thereby such; forinstance, by a belt or gear connection and it is, therefore, unnecessaryto illii'sf trate any particular means for this purpose. The,

sprags may be energized by any suitable means but as shown, expansiongarter springs H engage notches in the opposite ends of the sprags andexert sufi'icient torque on each sprag to hold it in frictionalengagement with the member B and the coil E. The force exerted by thesesprings H is not, however, sufficient to overcome the contractile forceexerted by the helical coil E.

In the modified construction shown in Fig. 4,

a helical member I surrounds the inner race member J normally in closeproximity thereto but out of frictional contact therewith. The sprags Kare between the member I and the outer race member L. To engage theclutch the ends of the 'member I are relatively movedto contract thediameter of this member thereby frictionally engaging the race member Jwhereupon the sprags K couple the same to the outer race member.

What I claim as my invention is: 1. A clutch comprising coaxialrelatively rotatable members having spacedcylindrical races, a resilientmember having one or more convolutions arranged adjacent to one of saidraces but normally out of frictional contact therewith,

sprags in the space between said resilient member and the other of saidraces, and means for relatively moving the opposite ends of saidresilient member to change the diameter thereof; and bring said memberinto frictional contact with the adjacent race.

2. A, clutch comprising coaxial relatively rotatable members havingspaced cylindrical races,

tional engagement with the member C but at any time the clutch may beengaged by momentarily stopping the and E of the'coil. Such stopping maybe effected by any suitable tripping mechanism, such as a lever G,normally clearing the a resilient member formed in one or moreconvolutions with oppositely extending end portions. said resilientmember being arranged in close proximity to but normally out offrictional contact with one of said races. a series of sprags betweensaid resilient member and the other of said -aresilient member :formedin one ormore coniient member :and the other of said "races an .an- 1 3races, means .forrelativelyimoving said end ;.portionscircumferentially' to change the diameter of said resilient membersozasto Irictionaily engage the adjacent race, and means for auto-.matically energizing saidsprags tomaintainathe frictional engagementbetween-the .same-zandsaid resilient member.

3. A clutch comprising coaxial relatively :rotatable members havingspaced cylindrical races,

VOilltiOns with axially projecting end portions,

said :resilientzmember being in :close proximity to butnormally-xout offrictional: contact with-toneof said. races, a series of spra'gs'between said zresilchor connection between the latter race and one endportion ofsaid resilientmemberpanmmeans for circumferentially moving"the other end of said resilient member relative to said anchored I.endto change'the 21381 ito ifri'otionally fjacentrace.

diameter of said resiiientmemengage the same with the :ad-

--4..-A clutch comprising coaxial relatively .ro-

:tatablezmembers: having spaced cylindrical races. I zoneof saidzmembers:being in rotation,v

.memberuformed. in' one or :more :convolutions with axially projectingportions being anchored to said .rotating "member a resilient endportions, one 50f. said end and .said resilient member .being positionedadd aathe .race of the other of said :relatively rotatable members, anda trip-tor engaging the .-..opposite wend TPDItlOII. "oflsaid resilientmember to imoveitheasame .circumferentially relative to said aanchored.endeportion .ameterof saidresilientmemberrto frictionally en-.gagevtheadjacent race and toiefiect a coupling between the same and therotating member.

thereby changing the dir-rvon J. "GRUENBERG.

